Since ink jet recording is noiseless and makes high-speed recording possible, it has been employed in terminal printers and has recently been rapidly spreading. Use of many ink nozzles makes it possible to carry out multicolor recording, and multicolor ink jet recordings based on various ink jet recording systems are available.
Water base inks comprising water as a principal component are used as this ink jet recording ink in terms of safety and recording characteristics, and in order to prevent clogging of nozzles and raise discharge characteristics, polyhydric alcohols are added in many cases.
Accordingly, recording sheets used for the above ink jet recording system have to satisfy various physical properties such as:
1 quickly absorbing a water base ink and not being blurred with the ink, PA1 2 excellent storage stability (images are not blurred by storage over a long period of time), PA1 3 high adhesion of a substrate to an ink-absorbing layer, PA1 4 no stickiness for convenience of handling, PA1 5 possible of continuously printing (no adhesion between sheets), and PA1 6 having high transparency in the case where the sheet is used for OHP (overhead projector). PA1 a. a dispersibility of silica is inferior, and the resulting sheet has a low transparency, PA1 b. in order to provide a sufficiently high stickiness resistance, a considerable amount thereof has to be compounded, and this exerts an adverse effect on a printing property and transparency, and PA1 c. the particles have an inferior dispersion stability in the coating liquid and settle down after storage over a long period of time (the particles which are stirred and dispersed immediately before coating hold bubbles and exert adverse effects on coating).
Satisfaction of these requirements depend largely on the characteristics of sheets used, and the existing situation is that recording sheets satisfying all of these required physical properties have not yet been found.
In order to improve, for example, a printing property, a drying property after printing, and stickiness, several recording sheets in which surfactants are compounded in ink-absorbing layers have been proposed (JP-A-60-56587, JP-A-60-198285, JP-A-61-132376, JP-A-1-146784, JP-A-1-146785, JP-A-4-214382, and JP-A-4-265784).
However, the recording sheets described in these publications are not sufficiently satisfactory in terms of a printing quality, which may be attributable to improper combination of water soluble polymers used and surfactants.